反应详情

温度

-20 °C

In 3 ml of acetic anhydride was dissolved 1.0 g of 3,4-diethoxycarbonyl-6-(4-methoxyethoxymethoxyphenyl)-2-pyridone, and the mixture was cooled to -20° C. and thereafter 0.2 ml of fuming nitric acid was added dropwise. After the mixture was stirred for 1 hour, water was added. After 2 hours' stirring at room temperature, the mixture was extracted with ethyl acetate. The organic layer was washed with an aqueous solution of sodium hydrogencarbonate, water and a saturated aqueous solution of sodium chloride, and dried. After the solvent was distilled off the resulting crystals were collected by filtration with diethyl ether.

1. stirringAfter 2 hours' stirring at room temperature
2. extractionthe mixture was extracted with ethyl acetate
3. washThe organic layer was washed with an aqueous solution of sodium hydrogencarbonate, water
4. dry with materiala saturated aqueous solution of sodium chloride, and dried
5. distillationAfter the solvent was distilled off the resulting crystals
6. filtrationwere collected by filtration with diethyl ether